1. Field of the Invention
This invention relates to a display device such as a direct-projection type of television receiver, a projection type display device, an image output device for a computer, etc., which utilizes a cathode-ray-tube (CRT), a liquid crystal device, a plasma device, an electroluminescence device, an electrochromic device or the like. Also, this invention related to a method for displaying an image.
2. Description of the Prior Art
When a color image is displayed with plural dots in a conventional display device, plural colored areas such as A-colored area, B-colored area, C-colored area, D-colored area, etc., are separately displayed for any color image. Also, in both cases of monochromatic image and color image, the image is displayed with areas having different brightness being separated respectively. In this display manner, a mixing color frequently occurs at a boundary between the different colored areas on the display device, and thus a clear image can not be displayed. Also, color becomes ambiguous at a boundary between the areas having different brightness. This is not only because of the problem of the ability of the display device, but also because high frequency components in the image signal are cut when the image signal is created or processed to send the image signal to the display device, that is, before the image signal is received by the display device. The signal waveform becomes gentle by the cut. This becomes a problem particularly in the case of the display for office automation which requires high definition.
In order to overcome the above disadvantage, the following method has been adopted.
That is, as shown in FIG. 3, an original image data 1 is subjected to a profiling processing to obtain a profile image data 2, and then the original image data 1 and the profile image data 2 are synthesized with each other to obtain a synthesized image data 3, thereby displaying the synthesized image data 3 on the display device.
However, this method requires a very high-speed calculation per frame, and thus has been unsuitable for a dynamical image displaying operation which requires a displaying speed above 60 frames per second.